Which term describes dead tissue due to decreased perfusion?

The term that best describes dead tissue due to decreased perfusion is "infarction." Infarction occurs when blood flow (perfusion) to a specific area of tissue is completely interrupted, leading to tissue death. This often happens due to an obstruction, such as a blood clot, preventing oxygenated blood from reaching the tissue.

Understanding ischemia, although related, is different as it refers to inadequate blood flow that may not result in immediate tissue death. Necrosis is the death of cells or tissue due to injury or lack of blood flow but does not specifically address the cause being a lack of perfusion. Hypoxia refers to a condition where there is a deficiency in oxygen reaching the tissues, which can occur with or without decreased blood flow. Therefore, infarction precisely defines the situation where decreased blood flow leads to tissue death, making it the most accurate answer.